ESP8266 as a gateway and controller?

Hi there I am new to this forum and I just discovered MySenors and what seems to be amazing endless possibilities very easily accessible!

I apologize if there is already the answer to my question in the forum, I looked but did not find any topics on my particular questions. If I missed it please point me in the right direction.
Here is what I am trying to do:

offline (no connection to the internet)

I would like to use a esp8266 as a gateway to talk to arduino node with nrf24l01 (both the arduino nodes and the esp8266 gateway would have nrf24l01 attached)

I would like to be able to connect to the esp8266 in softap mode using my smart phone as GUI (using a browser or a specific app).

So my understanding is that the controller would be hosted on the esp8266. Is that even possible? Or could the controller be on the smartphone and use the esp8266 wifi as a bridge only?

I guess it is easy with a rPi but I am trying to find a solution with a ESP8266 because of the cost difference.
Many thanks in advance for your answers!

@olivier
hello.
Sorry, no controller hosted. in fact it was more something like "scene" or actions etc..And for this purpose I think I will use multiple cheap tablet.
That said, your point 3) is something I have started for fun, but I have no release date..and I'm using a rpi controller. so it's not hurry for me, but I thought that could be interesting feature. but generally if you have no controller.
if you have router etc..you can setup your external acces from internet etc...
I'm not sure if esp8266 is great choice for a controller, or with less features and security..

Thank you for your answer. It looks like I cannot really host a controller on a ESP8266...
So would it be possible to use my sensors library without a controller?
For example would any of these feature work without a controller?

sending data between a node and a gateway (both ways)

have the gateway give a node an ID

ota firmware update (with mysbootloader)

I could then develop a firmware on the ESP8266 to have it host a website in softap mode so that a smartphone could see the data.

@olivier
yes that's what i said. you can set id static in sketch for instance. or for a gw allowing id that would need more work and study.
but what i have started is something like that. id static, captive portal for esp with spiffs storing settings, no website stored on esp, for performance, I have preferred esp8266 websocket server (faster), or mqtt (could be doable). And a mobile app (apk, i have no iphone) with cordova ionic (angular js etc...).
That's lot of work to do, for basic features if you compare to a true controller. But I agree that could be fun

Hi. I made what you are looking for. The basic idea is that every node has is own uniqueID, then, when a node ask to de Wateway for a node number, it is taked from a table.
Of course, I meade some modification to library to do that.